For North Carolina senior defensive tackle Tim Jackson, it was inexcusable.

It wasn’t just the sight of East Carolina players celebrating in his team’s end zones that irked him during UNC’s 55-31 loss Saturday, but the way in which the Pirates got there — with unrelenting speed.

“We’ve practiced against it all training camp so that’s not an excuse. Tempo is not an excuse,” Jackson said. “We played against a high tempo team — all in the spring and all in training camp — so at the end of the day it’s about not getting the job done.”

Since Jackson and the rest of the Tar Heels met coach Larry Fedora, who brought the new team philosophy “Smart, Fast and Physical” to Chapel Hill two years ago, UNC has lived and breathed speed.

The Tar Heel offense learned to be fast, running plays and putting points on the scoreboard without wasting time huddling, while the defense was taught to harness the high pace on the practice field.

But in the loss, Jackson and the Tar Heels were beaten at their own game, left distraught and blinded by the Pirates’ scorching speed on offense.

ECU’s own version of the no-huddle offense ran 101 plays, the most in history by an opponent against the Tar Heels, setting the pace with an 11-play, 73-yard game-opening drive in 3:32 — averaging less than 20 seconds per play.

All of ECU’s seven touchdown drives clocked in at less than five minutes.

“Their tempo is a lot faster than it’s been in the past years and what we’ve seen on film,” senior defensive end Kareem Martin said. “I guess we weren’t really expecting them to go as fast as they did. And I guess we settled in late but we still didn’t really play to their tempo.”

Fedora said UNC’s game plan was to eliminate ECU’s running game by forcing junior Pirate quarterback Shane Carden to rely on his arm to score.

But ECU’s high-tempo scheme allowed both its ground and passing games to take off to a tune of 603 total yards of offense.

For Martin, UNC’s problems on defense continue to heavily rely on the two words he repeatedly mentioned in his postgame interview — missed tackles.

After missing 21 tackles in their last game against Georgia Tech, the Tar Heels struggled again to take players to the ground.

“A lot of it’s just heart,” redshirt sophomore linebacker Jeff Schoettmer said. “If you have that will to tackle a guy, then you can. I feel like guys are getting in the right spots but we just aren’t finishing.”

But the problem that left Jackson questioning his team’s defensive fortitude revolved around something UNC has been accustomed to under Fedora — speed.

Because on Saturday at Kenan Stadium, East Carolina proved to be the smarter, more physical and, above all, faster team.

“It’s just something we should have been able to contain,” Martin said, “but when it’s going fast like that it’s hard to stop anything.”